DNA

biology · genetics · cells

Twisted ladder. DNA is shaped like a spiral staircase called a double helix, with two long strands coiling around each other.

Life's instructions. DNA carries the genetic instructions for how living things grow, work, and reproduce, kind of like a recipe book for your body.

In everything alive. All known living organisms, and even many viruses, use DNA to store their genetic information.

Big and important. DNA is a nucleic acid, one of the four major building-block molecules that all known life needs, along with proteins, fats, and carbohydrates.

Chemical cousin. DNA has a close relative called RNA, another nucleic acid that helps cells use the instructions DNA stores.